floor

#include <math.h>float floorf(float num);double floor(double num);
long double floorl(long double num);

floorf( ) and floorl( ) were added by C99.

The floor( ) family of functions returns the largest integer (represented as a floating-point value) not greater than num. For example, given 1.02, floor( ) would return 1.0. Given –1.02, floor( ) would return –2.0.

Related functions are fceil( ) and fmod( ).